EFFECT OF HIGH HYDROSTATIC PRESSURE ON FRUIT JUICES AND OTHER VEGETABLES AND THEIR DERIVATIVES

Amadeu Bernaus Ramírez, Universitat Autònoma de Barcelona June 2018

OBJECTIVES

• To present a treatment method that is increasingly usednowadays in food industry.

• To show the impact that high hydrostatic pressure produces onfoods, specifically on juices.

• To compare high hydrostatic pressure with other thermal andnon-thermal technologies.

CONCLUSION• Enzymes are partially inactivated, antioxidant activity is higher than untreated juices and vitamin remain stable.

• Spores are resistant but they can be inactivated in a two stage process, bacteria and moulds & yeasts are inactivated.

• No significant changes are detected in L*, a*, b* and E after treatment, either in taste and aroma parameters.

• The quality of HHP-treated fruit and vegetable products exhibit less variations than thermal treated samples.

• The effects of the evaluated non-thermal technologies are similar to HHP ones.

HIGH HYDROSTATIC PRESSURE

THERMAL TECHNOLOGIES NON-THERMAL TECHNOLOGIES

MICROBIOLOGICAL EFFECTS

ORGANOLEPTIC EFFECTSPHYSICOCHEMICAL EFFECTS• Enzymes- High pressure produces changes and

therefore, enzymes lose activity.

- PME 600 MPa 5/25 min, 18.8% - 49.6%

- PPO 600 MPa 5/25 min, 45,1% - 81,2%

• Antioxidants- HHP disrupts cell walls improving the

extractability of the phenolic compounds.

- Content and bioaccessibility of phenoliccompounds increased by approximately35%, in fruit drinks treated at 400 MPa/5min

• Vitamins - 90% retention on average of ascorbic acid in

samples treated at (400-600MPa).

- After HHP treatment, vitamin C did notshow changes compared to untreatedsamples

• Spores - 250MPa/ TºC

- Extremely resistant to pressure.

• Bacteria

- Are inactivated by HHP, nevertheless pressurecan cause them sublethal damage.

• Mould & Yeasts

- Sensitive to HPP, but ascospores are resistant.

• Colour- Juice colour showed few differences

compared to untreated samples.

• Taste- The general acceptance of grape juice treated

by pressure was quite similar to fresh juice.

• Aroma- Juices retain typical sensory and organoleptic

characteristics of the fresh product.

• PPO• PME

• Vitamin C

1st GERMINATION

2nd INACTIVATION

Pasteurization Flash Pasteurization

Sterilization PEF UHPH Ultrasound

• Loss of phenolic compounds, sensory and nutritionalproperties.

• Thermal treatment guarantees complete inactivation ofmicroorganisms and enzymes throughout their shelf life.

• Very similar effects compared to HHP.

• It has been seen that UHPH can totally inhibit enzymes and more microorganisms than HHP.

BIBLIOGRAPHY

1. Esquema de funcionamientode una unidad de HPP. (Figure)retrieved May 29,2018 from:https://www.hiperbaric.com/es/alta-presion

2. (Figure) retrieved May 22,2018 from:https://thenounproject.com

FIGURE 1. High hydrostatic pressure treatment process

FIGURE 2. Simulation of the properties of a juice treated by HHP